It's no shock that many Republicans have been sharply critical of Veterans Affairs Secretary Eric Shinseki, with some even calling for his resignation in the wake of allegations of misconduct at VA medical facilities across the country.

What's more surprising, though, is the growing number of Democrats who have piled on.

Three Democratic candidates for the U.S. Senate in 2014 have called for Shinseki's dismissal in recent days.

"We owe a solemn obligation to our veterans, and our government defaulted on that contract," Grimes said in a statement. "I don't see how that breach of trust with our veterans can be repaired if the current leadership stays in place."

McConnell, for his part, hasn't explicitly called for Shinseki to resign, but he said on Fox last Sunday that "it's obvious that the management team needs to be changed in order to address this problem."

Michelle Nunn, the daughter of longtime Georgia Sen. Sam Nunn who's seeking an open Senate seat in Georgia, said Friday there's "growing evidence the Department of Veterans Affairs needs new leadership," according to the Associated Press. She added she hopes Shinseki resigns.

And Democrat Rick Weiland, who's seeking an open seat in South Dakota, similarly called for Shinseki to step down on Thursday, though he also slammed House Republicans for helping create the VA health care crisis in the first place by cutting the budget and shutting down the government.

It's worth noting that Grimes, Nunn, and Weiland, as Democrats seeking statewide office in heavily Republican states, have more incentive than most to distance themselves from the administration. If the friendly fire starts coming from Democrats on safer political terrain, it could spell real trouble for the embattled secretary.

Even some onetime allies -- including former GOP Senate Majority Leader Bob Dole, who introduced Shinseki at his confirmation hearing in 2009 -- have acknowledged the secretary is on thin ice.

Dole told USA Today on Thursday that the secretary should stay until an internal investigation into the scandal is completed. Then "you see what you can lay at his feet and what his response has been," Dole added. "If the facts reveal that he neglected his duties, then he should go."